Non‐sebaceous lymphadenoma‐like mucoepidermoid carcinoma: A case report

摘要

Abstract Non‐sebaceous lymphadenoma is a rare benign salivary gland tumor comprised of non‐sebaceous epithelial cells and lymphoid tissue. Although its clinicopathological features have been described, its histogenesis and genetic background have not yet been elucidated. MAML2 rearrangement and the resultant CRTC1/3‐MAML2 fusion gene are well‐known specific genetic changes in mucoepidermoid carcinoma. Here, we present a case of lymphoepithelial tumor characterized by histomorphology of the non‐sebaceous lymphadenoma and CRTC1‐MAML2 fusion gene. The patient was an 83‐year‐old woman with an 8‐year history of a solid, well‐circumscribed tumor in the parotid gland. Histologically, the tumor was surrounded by thin fibrous connective tissue and was composed of tubular‐cystic and solid nests of epithelial cells equally distributed in the lymphoid tissue. The histological features were suggestive of non‐sebaceous lymphadenoma. Although the histomorphology was not consistent with mucoepidermoid carcinoma, a diagnosis of non‐sebaceous lymphadenoma‐like mucoepidermoid carcinoma was made based on the presence of the CRTC1‐MAML2 fusion gene. The histological features alone could not establish the diagnosis, and ancillary molecular analysis was required.